Da Vinci's equestrian statue, 500 years in the making.

The odd depiction of the Virgin Mary and baby Jesus is rooted in the Catholic Church's eradication of Catharism.

Lady Liberty's original designer installed a little clone in this French fountain.

The world's largest reflecting pool is just two centimeters deep.

This Bordeaux parking garage has 712 indoor spaces, and one outdoor.

A 141-foot wave of crashing lumber guards the entrance to the Grand Place in Mons.

This modern arts center is built around a gem of late-Baroque architecture.

The "Greatest Sewer" of ancient Rome is one of the oldest sewer systems in the world, and is still in use.

The only university zoological museum in London houses extinct animals, bizarre natural history specimens, and a Micrarium of microscopic creatures.

One of the few remaining casualties of the London Blitz, this destroyed church has become an enchanting public garden.

Kings Cross Station pays tribute to its role in Britain's best-selling book series.

London's smallest police station is barely the size of a phone booth.

The television series' iconic giant foot was borrowed from this classical painting.

The Metropolitan Police refurbished the blue box (perhaps not coincidentally) the same year "Doctor Who" returned to TV screens.

A wonderfully kitsch bookstore the size of a supermarket.

Ancient man-made caves underneath small town Belgium.

Hiding the longest subterranean river known in the world.

A Museum of Psychiatry in a still-operating mental institution.

This fairytale castle was built as a show of power but was nearly torn down thanks to its history of torture.

Only museum in the world devoted to bookbinding and book arts holds a permanent collection representing five centuries.

Theme park featuring miniature replicas of European monuments.

Climb inside an iron crystal magnified 165 billion times its normal size.

A little sculpture with a large wardrobe.

Cozy basement bar sports an inventory of over 2,000 beers.